<?php
class AuditConfig
{
	private $filename;
	private $completionLabel;
	private $completionValue;
	private $sortByLabels;
	private $regionFieldList;
	private $includeRules;
	private $sortRegion;
	private $ifBlanks;
		
	public function __construct($filename)
	{
		$this->filename = $filename;
		
		// set some defaults
		$this->completionLabel = "Status";
		$this->completionValue = "Completed";
		$this->sortByLabels = array("Actual Date", "Due Date");
		$this->ifBlanks = array();
	
		$this->loadConfig();
	}
	
	public function getCompletionValue()
	{
		return $this->completionValue;
	}

	public function getCompletionLabel()
	{
		return $this->completionLabel;
	}
	
	public function getSortByLabels()
	{
		return $this->sortByLabels;
	}
	
	public function getIfBlanks()
	{
		return $this->ifBlanks;
	}
	
	public function loadConfig()
	{
		$this->regionFieldList = array();
		$this->includeRules = array();
				
		$doc = new DOMDocument();
		if ($doc->load(dirname( __FILE__ ) . '/' . $this->filename))
		{
			$regions = $doc->getElementsByTagName("region"); 
			foreach($regions as $region) 
			{
				$regionName = $region->getAttribute("name");
				$this->regionFieldList[$regionName] = array();

				// Inclusion/exclusion settings
				$includeRule = $region->getAttribute("includeRule");
				if (empty($includeRule))
				{
					$includeRule = 'include';
				}
				$this->includeRules[$regionName] = array('rule' => $includeRule);
				if ($includeRule == 'exclude')
				{
					$altRegion = $region->getAttribute("exclusionCorrespondingRegion");
					$this->includeRules[$regionName]['altRegion'] = $altRegion;
				}

				// Time component display settings
				$includeTime = $region->getAttribute("includeTime");
				if (empty($includeTime))
				{
					$includeTime = 'false';
				}
				$this->includeRules[$regionName]['includeTime'] = $includeTime;
									
				$fieldCount = 0;									
				$fields = $region->getElementsByTagName("field");
				foreach($fields as $field)
				{
					/* Storing them this way, which is backwards to how you might normally
					have arrays with a numeric key and a text value, ends up making things better
					in the other functions, in particular the sorting and also inRegion should end
					up being more efficient (searching for a key instead of a value). */ 
					$this->regionFieldList[$regionName][$field->nodeValue] = $fieldCount;
					
					// Field-level overrides of time component display settings
					$includeTime = $field->getAttribute("includeTime");
					if (! empty($includeTime))
					{
						$this->regionFieldList[$regionName][$field->nodeValue]['includeTime'] = $includeTime;
					}
					
					// ifBlank attribute
					$ifBlank = $field->getAttribute("ifBlank");
					if (! empty($ifBlank))
					{
						$this->ifBlanks[$regionName][$field->nodeValue] = $ifBlank;
					}
					
					$fieldCount++;
				}
			}
			
			$completionStatus = $doc->getElementsByTagName("completionStatus");
			if (! empty($completionStatus))
			{
				$label_elements = $completionStatus->item(0)->getElementsByTagName("label");
				$this->completionLabel = $label_elements->item(0)->nodeValue;
				
				$value_elements = $completionStatus->item(0)->getElementsByTagName("value");
				$this->completionValue = $value_elements->item(0)->nodeValue;
			}

			$sortElement = $doc->getElementsByTagName("sortByLabels");
			if (! empty($sortElement))
			{
				$this->sortByLabels = array();
				$label_elements = $sortElement->item(0)->getElementsByTagName("label");
				foreach($label_elements as $ele)
				{
					$this->sortByLabels[] = $ele->nodeValue;
				}
			}

		}		
	}
	
	/* inRegion
	 * 
	 * Check if label $n is explicitly listed in region $r in the config.
	 */
	public function inRegion($n, $r)
	{
		if (empty($this->regionFieldList[$r]))
		{
			return false;
		}
		else
		{
			return array_key_exists($n, $this->regionFieldList[$r]);
		}
	}
	
	/* includeInRegion
	 * 
	 * Should field $n be included in region $r, taking into account exclusion rules.
	 */
	public function includeInRegion($n, $r)
	{
		$add_it = false;
		$rules = $this->includeRules[$r];
		if ($rules['rule'] == 'exclude')
		{
			if ( !$this->inRegion($n, $r) && !$this->inRegion($n, $rules['altRegion']) )
			{
				$add_it = true;
			}
		}
		elseif ($this->inRegion($n, $r))
		{
			$add_it = true;
		}
		return $add_it;
	}
				
	/* includeTime
	 * 
	 * Should the time component of field $n in region $r be displayed?
	 */
	public function includeTime($n, $r)
	{
		$retval = false;
		if (empty($this->regionFieldList[$r][$n]['includeTime']))
		{
			// No field-level override, so look at the region's settings
			if (! empty($this->includeRules[$r]['includeTime']))
			{
				$retval = $this->includeRules[$r]['includeTime'];
			}
		}
		else
		{
			$retval = $this->regionFieldList[$r][$n]['includeTime'];
		}
		
		// There's a mix of strings and boolean, so convert any strings.
		if ($retval == 'false')
		{
			$retval = false;
		}
		elseif ($retval == 'true')
		{
			$retval = true;
		}
		
		return $retval;
	}
	
	/* getRegions
	 * 
	 * Return a list of all the regions in the config file.
	 */
	public function getRegions()
	{
		return array_keys($this->regionFieldList);
	}

	/* sort
	 * 
	 * Sort a group of fields for a given region according to the order in the config.
	 * The array to be sorted should have elements that have a member with a key of 'label', and the value should be the field label.
	 */
	public function sort(&$f, $r)
	{
		// For exclusion-type regions, there's nothing to do, because we won't have been given any ordering.
		if ($this->includeRules[$r]['rule'] == 'exclude')
		{
			return;
		}
		
		$this->sortRegion = $r;
		uasort($f, array(&$this, "compareFields"));
	}
	
	/* compareFields
	 * 
	 * This is intended to be called as a sort callback function, returning whether a field in a region comes before or after another one.
	 * See also PHP's usort().
	 */
	public function compareFields($a, $b)
	{
		if (empty($this->regionFieldList[$this->sortRegion][$a['label']]))
		{
			$x = 0;
		}
		else
		{
			$x = $this->regionFieldList[$this->sortRegion][$a['label']];
		}

		if (empty($this->regionFieldList[$this->sortRegion][$b['label']]))
		{
			$y = 0;
		}
		else
		{
			$y = $this->regionFieldList[$this->sortRegion][$b['label']];
		}
		
		return $x - $y;
	}
}

